27 October, 2009

Recently hub generators have drawn a lot of current in the bike blogs, but there is good reason to favor the old bottle generator. A good sidewall dynamo creates a bit more drag than a hub generator, but only when in use. Unlike a hub generator, it creates no additional drag when in the "off" position. You can change wheels without losing power. And bottle dynamos cost a lot less. I also like the retro look of a bottle generator. On the down side, they can slip in wet conditions if not carefully set up and can eventually wear down the side of your tire.

Many of you asked for 27" rims so we have the CR-18 in that size. Though I still think that for bikes that don't have historic significance a switch to 700c wheels should be considered.

We like bottle dynos, but if you consider yourself a bit on the klutzy side, pony up for a dynohub -- sidewall rollers can go to heck fast if knocked out of alignment. Plus, you can move that dynohub wheel between different bikes to make the most of the admittedly more expensive solution -- and with a Low-Down 2 QR-nut mount, the light goes with the wheel! Another argument for standardizing on one wheel size in one's fleet.

FYI, Spanninga dynamo is good value for money. I've used one of these, I've got two on my kids' bikes, one of them always-on (safety-first).

However, you are correct about slippy-when wet, and also slippy-on-some-tire-compounds-when-cold. That's what eventually drove me to a dynamo hub.

I've also spent money (in years past) on a fancy B&M sidewall dynamo, which no longer works (not water-tight, bearings eventually crapped out). Not good value for my money, didn't get useful help from distributor or manufacturer, better to buy this one, at least if it fails it was cheap (and mine, except for the spring on one, have not failed yet).

Ditto on the sidewall dynamo criticisms. Rode with Niterider 12v for years on my almost 2hr. daily round trip commute. Tried a Spanniga sidewall last year as a backup - not for me, way too much drag, even when set up right. Bought a Schmidt Dynohub, can't notice any drag, even with the LED light on.

Anybody ever had a bottle dynamo just quit working in subzero (Fahrenheit) cold? Slipping isn't the problem, it just won't generate any power unless I warm it back up. Problem is intermittent. Ideas? And does this ever happen with generator hubs?

Otherwise, I agree with Chris on the bottle dynamo's merits. Even the looks.